Ignition coil and method of assembly

ABSTRACT

An ignition coil for delivering a spark-generating current to a spark plug includes a magnetically-permeable core; a primary winding disposed outward of the core; and a secondary winding disposed outward of the primary winding and inductively coupled to the primary winding. The secondary winding terminates at one end thereof in a low-voltage end and terminates at another end thereof in a high-voltage end. At least one of the low-voltage end of the secondary winding and the high-voltage end of the secondary winding is electrically connected directly to a terminal through an electrically conductive polymer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims the benefit of U.S. provisional patentapplication Ser. No. 61/917,588 filed on Dec. 18, 2013, the disclosureof which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD OF INVENTION

The present invention relates to an ignition coil for developing aspark-generating current that is applied to one or more spark plugs ofan internal combustion engine.

BACKGROUND OF INVENTION

Ignition coils are known for use in connection with an internalcombustion engine such as an automobile engine. Ignition coils typicallyinclude a core around which is wound a primary winding. A secondarywinding is wound around a secondary winding spool to surround theprimary winding such that a high voltage is induced on the secondarywinding when an electric current applied to the primary winding isstopped. One end of the secondary winding is a low voltage end which isconnected to a ground terminal while the other end of the secondarywinding is a high voltage end which is connected to a high voltageterminal which is in electrical communication with a spark plug, therebydelivering a spark-generating current to the spark plug.

Connecting the low voltage end and the high-voltage end of the secondarywinding to their respective terminals may be complex and costly. Inorder to attach the low-voltage end of the secondary winding to thelow-voltage terminal, the low-voltage end is wrapped onto thelow-voltage terminal, and then dipped into solder in order to strip thewire and make the electrical connection. In order to attach thehigh-voltage end of the secondary winding to the high-voltage terminal,the high-voltage end of the secondary winding is wrapped onto thehigh-voltage terminal, and then dipped into solder in order to strip thewire and make the electrical connection. Due to the high-voltageterminal being at high-voltage in use, they typically need to be bentand formed to minimize electric field concentrations at the tip. In thecase of both the low-voltage end and the high-voltage end of thesecondary winding, the terminals need to be assembled to the spool andterminated, then formed in some manner. Furthermore, a resistor istypically added between the secondary winding and the spark plug inorder to suppress radio frequency interference (RFI). The addition of aresistor adds additional cost to the system.

Korean Patent No. KR970005493 teaches using a conductive epoxy toprovide electric communication between a terminal pin and an externalterminal. However, the terminal pin must still be connected to thehigh-voltage end of the secondary winding in a conventional manner.

What is needed is an ignition coil which minimizes or eliminates one ormore of the shortcomings as set forth above.

SUMMARY OF THE INVENTION

Briefly described, an ignition coil is provided for delivering aspark-generating current to a spark plug. The ignition coil includes amagnetically-permeable core, a primary winding disposed outward of thecore, and a secondary winding disposed outward of the primary windingand inductively coupled to the primary winding. The secondary windingterminates at one end thereof in a low-voltage end and terminates atanother end thereof in a high-voltage end. At least one of thelow-voltage end of the secondary winding and the high-voltage end of thesecondary winding is electrically connected directly to a terminalthrough an electrically conductive polymer.

A method is also provided for assembling an ignition coil for deliveringa spark-generating current to a spark plug where the ignition coilincludes a magnetically-permeable core, a primary winding disposedoutward of the core, and a secondary winding disposed outward of theprimary winding and inductively coupled to the primary winding such thatthe secondary winding terminates at one end thereof in a low-voltage endand the secondary winding terminates at another end thereof in ahigh-voltage end. The method includes providing an electricallyconductive polymer and using the electrically conductive polymer todirectly electrically connect at least one of the low-voltage end of thesecondary winding and the high-voltage end of the secondary winding to aterminal through the electrically conductive polymer.

The ignition coil and method of assembling the ignition coil eliminatesthe need for processing steps for preparing the ends of the secondarywinding and soldering the ends of the secondary winding to respectiveterminals.

BRIEF DESCRIPTION OF DRAWINGS

This invention will be further described with reference to theaccompanying drawings in which:

FIG. 1 is a simplified cross-section view of an ignition coil inaccordance with the present invention taken through a first plane;

FIG. 2 is a simplified cross-section view of the ignition coil of FIG. 1taken through a second plane that is substantially parallel to the firstplane through which FIG. 1 is sectioned;

FIG. 3 is an elevation view of a case of the ignition coil of FIGS. 1and 2 looking in the direction of arrow B of FIG. 1;

FIG. 4 is an enlarged portion of FIG. 1 showing a high-voltage end of asecondary winding;

FIG. 5 is an enlarged portion of FIG. 2 showing a low-voltage end of thesecondary winding; and

FIG. 6 is an alternative arrangement for a high-voltage recess of theignition coil in accordance with the present invention.

DETAILED DESCRIPTION OF INVENTION

Reference will first be made to FIGS. 1 and 2 which show simplifiedcross-section views of an ignition coil 10 where FIGS. 1 and 2 aresectioned by parallel planes. Ignition coil 10 may be controlled by acontrol unit 12 or the like. Ignition coil 10 is configured forconnection to a spark plug 14 that is in threaded engagement with aspark plug opening (not shown) in an internal combustion engine (alsonot shown). Ignition coil 10 is configured to deliver a high-voltagespark-generating current to spark plug 14, as shown. Generally, overallspark timing (dwell control) and the like is provided by control unit12. One ignition coil 10 may be provided per spark plug 14.

Ignition coil 10 may include a magnetically-permeable core 16, amagnetically-permeable structure 18, hereinafter referred to ashigh-permeance structure 18, configured to provide a high permeancemagnetic return path which has a base section 20 and a pair of legs 22and 24, a primary winding spool 26, a primary winding 28, a quantity ofencapsulant 30 such as an epoxy potting material, a secondary windingspool 32, a secondary winding 34, a case 36, a low-voltage connectorbody 38 having primary terminals 40 a, 40 b, a high-voltage tower 42,and a high-voltage terminal 44.

Core 16 extends along a core longitudinal axis A. Core 16 may be made oflaminated steel plates, compression molded insulated iron particles, orother appropriate material. Core 16 may be any cross-sectional shapeknown to those of ordinary skill in the art, for example only, oval orcircular.

Primary winding spool 26 is configured to receive and retain primarywinding 28. Primary winding spool 26 is disposed adjacent to andradially outward of core 16 and is preferably in coaxial relationshiptherewith. Primary winding spool 26 may comprise any one of a number ofconventional spool configurations known to those of ordinary skill inthe art. In the illustrated embodiment, primary winding spool 26 isconfigured to receive one continuous primary winding. Primary windingspool 26 may be formed generally of electrical insulating materialhaving properties suitable for use in a relatively high temperatureenvironment. For example, primary winding spool 26 may comprise plasticmaterial such as PPO/PS (e.g., NORYL® available from General Electric)or polybutylene terephthalate (PBT) thermoplastic polyester. It shouldbe understood that there are a variety of alternative materials that maybe used for primary winding spool 26.

Primary winding 28, as described above, is wound onto primary windingspool 26. Primary winding 28 includes first and second ends that areconnected to the primary terminals 40 a, 40 b in low-voltage connectorbody 38. Primary winding 28 is configured to carry a primary currentI_(P) for charging ignition coil 10 upon control of control unit 12.Primary winding 28 may comprise copper, insulated magnet wire, with asize typically between about 20-23 AWG.

Secondary winding spool 32 is configured to receive and retain secondarywinding 34. Secondary winding spool 32 is disposed adjacent to andradially outward of the central components comprising core 16, primarywinding spool 26, and primary winding 28 and, preferably, is in coaxialrelationship therewith. Secondary winding spool 32 may comprise any oneof a number of conventional spool configurations known to those ofordinary skill in the art. In the illustrated embodiment, secondarywinding spool 32 is configured for use with a continuous windingstrategy (e.g., progressive winding) where secondary winding 34 is wounduninterrupted around secondary winding spool 32. However, it should beunderstood that other known configurations may be employed, such as, forexample only, a segmented winding strategy where a plurality of axiallyspaced ribs on secondary winding spool 32 forms a plurality of channelstherebetween. Secondary winding spool 32 may be formed generally ofelectrical insulating material having properties suitable for use in arelatively high temperature environment. For example, secondary windingspool 32 may comprise plastic material such as PPO/PS (e.g., NORYLavailable from General Electric) or polybutylene terephthalate (PBT)thermoplastic polyester. It should be understood that there are avariety of alternative materials that may be used for secondary windingspool 32. Further features of secondary winding spool 32 will bedescribed in greater detail later.

Secondary winding 34 includes a low-voltage end 46 (shown in FIG. 2) anda high-voltage end 48 (shown in FIG. 1). Low-voltage end 46 may beelectrically connected to a low-voltage terminal 50 within case 36 whichis connected to ground by way of a ground connection through low-voltageconnector body 38. The electrical connection of low-voltage end 46 tolow-voltage terminal 50 will be discussed in greater detail later.High-voltage end 48 is electrically connected to high-voltage terminal44 as will also be discussed in greater detail later. Secondary winding34 may be implemented using conventional approaches and material (e.g.copper, insulated magnet wire) known to those of ordinary skill in theart.

High permeance structure 18 is configured to provide a high permeancemagnetic return path for the magnetic flux produced in core 16 duringoperation of ignition coil 10. High permeance structure 18 may beformed, for example, from a stack of silicon steel laminations or otheradequate magnetic material. As described previously, high permeancestructure 18 includes base section 20 and a pair of legs 22 and 24. Core16 is positioned between legs 22 and 24 such that core longitudinal axisA passes through legs 22 and 24. One end of core 16 mates with leg 22while the other end of core 16 forms a gap with leg 24 where the gap maybe in a range of, for example only, about 0.5 mm to about 2 mm. Furtherfeatures of high permeance structure 18 are described in United StatesPatent Application Publication No. US 2013/0291844 A1 to Skinner et al.,the disclosure of which is incorporated herein by reference in itsentirety.

Reference will continue to be made to FIGS. 1 and 2 and additionalreference will now be made to FIG. 3 which shows an elevation view ofcase 36 viewed in the direction of arrow B shown in FIG. 1. Case 36defines a case interior 52 having an interior surface 54. Core 16, highpermeance structure 18, primary winding spool 26, primary winding 28,secondary winding spool 32, secondary winding 34, high-voltage terminal44, and low-voltage terminal 50 are located within case interior 52 butare not shown in FIG. 3.

Interior surface 54 of case 36 includes a low-voltage recess 56 therein.Low-voltage recess 56 includes a first low-voltage recess compartment 58and a second low-voltage recess compartment 60 such that firstlow-voltage recess compartment 58 and second low-voltage recesscompartment 60 are connected to each other by a low-voltage recesschannel 62. Low-voltage end 46 of secondary winding 34 is disposedwithin first low-voltage recess compartment 58 while low-voltageterminal 50 is disposed within second low-voltage recess compartment 60.An electrically conductive polymer 64 is disposed within firstlow-voltage recess compartment 58, second low-voltage recess compartment60, and low-voltage recess channel 62 such that electrically conductivepolymer 64 directly places low-voltage end 46 of secondary winding 34 inelectrical communication with low-voltage terminal 50. Electricallyconductive polymer 64 may be, for example only, an electricallyconductive epoxy or silicone and may contain, for example only about 15%to about 20% by volume carbon black.

Reference will continue to be made to FIGS. 1-3 and additional referencewill now be made to FIG. 5 which is an enlarged portion of FIG. 2. Inorder to facilitate insertion of low-voltage end 46 of secondary winding34 into electrically conductive polymer 64 during assembly, as will bedescribed in greater detail below, low-voltage end 46 of secondarywinding 34 may be wound around a low-voltage post 66 in order to providesupport thereto. Low-voltage post 66 extends outward from secondarywinding spool 32 and may be formed as an integral part thereof.Low-voltage post 66 may include a retention feature, illustrated aslow-voltage post step 68, for preventing low-voltage end 46 of secondarywinding 34 from sliding on low-voltage post 66 when low-voltage post 66and low-voltage end 46 of secondary winding 34 are pushed intoelectrically conductive polymer 64 during assembly as will be describedin greater detail later. While the retention feature has beenillustrated as low-voltage post step 68, it should now be understoodthat other retention features may be used, for example only, a pluralityof steps, ribs, barbs, or surface texture which prevents low-voltage end46 of secondary winding 34 from sliding on low-voltage post 66 whenlow-voltage post 66 and low-voltage end 46 of secondary winding 34 arepushed into electrically conductive polymer 64.

Again with reference to FIGS. 1-3, interior surface 54 of case 36 alsoincludes a high-voltage recess 70 therein. High-voltage recess 70includes a first high-voltage recess compartment 72 and a secondhigh-voltage recess compartment 74 such that first high-voltage recesscompartment 72 and second high-voltage recess compartment 74 areconnected to each other by a high-voltage recess channel 76.High-voltage end 48 of secondary winding 34 is disposed within firsthigh-voltage recess compartment 72 while high-voltage terminal 44 isdisposed within second high-voltage recess compartment 74. Electricallyconductive polymer 64 is disposed within first high-voltage recesscompartment 72, second high-voltage recess compartment 74, andhigh-voltage recess channel 76 such that electrically conductive polymer64 directly places high-voltage end 48 of secondary winding 34 inelectrical communication with high-voltage terminal 44. As describepreviously, electrically conductive polymer 64 may be, for example only,an electrically conductive epoxy or silicone and may contain, forexample only about 15% to about 20% by volume carbon black.

Reference will continue to be made to FIGS. 1-3 and additional referencewill now be made to FIG. 4 which is an enlarged portion of FIG. 1.Electrically conductive polymer 64 within high-voltage recess channel 76may be used to form a suppression resistance between first high-voltagerecess compartment 72 and second high-voltage recess compartment 74 forsuppressing radio-frequency interference (RFI) in use of ignition coil10. High-voltage recess channel 76 has a length L₇₆, a width W₇₆ and aheight H₇₆ which may each be tailored to hold a predetermined volume ofelectrically conductive polymer 64 which results in a predeterminedresistance between first high-voltage recess compartment 72 and secondhigh-voltage recess compartment 74. The predetermined resistance may be,for example only, between about 500 ohms and about 2000 ohms. Usingelectrically conductive polymer 64 within high-voltage recess channel 76for suppressing RFI reduces cost by eliminating the need for a separateresistor which is commonly used in ignition coils for suppressing RFI.

In order to facilitate insertion of high-voltage end 48 of secondarywinding 34 into electrically conductive polymer 64 during assembly, aswill be described in greater detail below, high-voltage end 48 ofsecondary winding 34 may be wound around a high-voltage post 78 in orderto provide support thereto. High-voltage post 78 extends outward fromsecondary winding spool 32 and may be formed as an integral partthereof. High-voltage post 78 may include a retention feature,illustrated as high-voltage post step 80, for preventing high-voltageend 48 of secondary winding 34 from sliding on high-voltage post 78 whenhigh-voltage post 78 and high-voltage end 48 of secondary winding 34 arepushed into electrically conductive polymer 64 during assembly as willbe described in greater detail later. While the retention feature hasbeen illustrated as high-voltage post step 80, it should now beunderstood that other retention features may be used, for example only,a plurality of steps, ribs, barbs, or surface texture which preventshigh-voltage end 48 of secondary winding 34 from sliding on high-voltagepost 78 when high-voltage post 78 and high-voltage end 48 of secondarywinding 34 are pushed into electrically conductive polymer 64.

In order to further enhance the suppression of RFI, high-voltage post 78may be a piece of steel that is press fit to secondary winding spool 32rather than being integrally formed with secondary winding spool 32.Consequently, high-voltage end 48 of secondary winding 34 together withhigh-voltage post 78 forms an inductor which enhances the suppression ofRFI. Alternatively, as shown in FIG. 4, an inductor 82 may be embeddedwithin electrically conductive polymer 64 within high-voltage recess 70.Inductor 82 may be, for example only, an iron core with insulated copperwire wound thereabout.

Encapsulant 30 may be suitable for providing electrical insulationwithin ignition coil 10. In a preferred embodiment, encapsulant 30 maycomprise an epoxy potting material. Sufficient encapsulant 30 isintroduced in ignition coil 10, in the illustrated embodiment, tosubstantially fill the case interior 52. Encapsulant 30 also providesprotection from environmental factors which may be encountered duringthe service life of ignition coil 10. There are a number of encapsulantmaterials known in the art.

Now with reference to FIG. 6, an alternative high-voltage recess 70′ isshown where a high-voltage terminal 44′ is press fit within high-voltagerecess 70′. In order to minimize the electric field concentrationbetween high-voltage terminal 44′ and the portion of case 36 with whichhigh-voltage terminal 44′ is press fit, high-voltage recess 70′ isarranged to surround the area of press fit between high-voltage terminal44′ and case 36. Consequently, electrically conductive polymer 64 willradially surround the portion of case 36 with which high-voltageterminal 44′ is press fit thereby providing the same voltage radiallyinward and outward of the portion of case 36 with which high-voltageterminal 44′ is press fit. In this way, the same effect taught in U.S.Pat. No. 8,564,392 to Skinner et al., the disclosure of which isincorporated herein by reference in its entirety, using a properlyshaped high-voltage terminal may be achieved while using a high-voltageterminal with a more simple geometry.

Now with reference to FIGS. 1-5, a method of assembling ignition coil 10will now be described where core 16, high permeance structure 18,primary winding spool 26, primary winding 28, secondary winding spool32, and secondary winding 34 are provided together as a subassembly suchthat low-voltage end 46 of secondary winding 34 has been wrapped aroundlow-voltage post 66 of secondary winding spool 32 and high-voltage end48 of secondary winding 34 has been wrapped around high-voltage post 78of secondary winding spool 32. First, high-voltage terminal 44 isdisposed within second high-voltage recess compartment 74 of case 36.Next, electrically conductive polymer 64 is dispensed, in liquid form,within low-voltage recess 56 and high-voltage recess 70. Morespecifically, electrically conductive polymer 64 is dispensed withinfirst low-voltage recess compartment 58, second low-voltage recesscompartment 60, low-voltage recess channel 62, first high-voltage recesscompartment 72, second high-voltage recess compartment 74, andhigh-voltage recess channel 76. It should be noted that high-voltageterminal 44 prevents electrically conductive polymer 64 from escapingfrom high-voltage recess 70 into high-voltage tower 42. Subsequently,while electrically conductive polymer 64 is still in liquid form, thesubassembly comprising core 16, high permeance structure 18, primarywinding spool 26, primary winding 28, secondary winding spool 32, andsecondary winding 34 is positioned within case interior 52 of case 36such that low-voltage post 66 together with low-voltage end 46 ofsecondary winding 34 are pressed into electrically conductive polymer 64within first low-voltage recess compartment 58 and such thathigh-voltage post 78 together with high-voltage end 48 of secondarywinding 34 are pressed into electrically conductive polymer 64 withinfirst high-voltage recess compartment 72 in the direction of arrow Bshown in FIG. 1. Low-voltage post step 68 prevents low-voltage end 46 ofsecondary winding 34 from sliding on low-voltage post 66 as low-voltageend 46 of secondary winding 34 is pressed into electrically conductivepolymer 64. Similarly, high-voltage post step 80 prevents high-voltageend 48 of secondary winding 34 from sliding on high-voltage post 78 ashigh-voltage end 48 of secondary winding 34 is pressed into electricallyconductive polymer 64. Also while electrically conductive polymer 64 isstill in liquid form, low-voltage terminal 50 is pressed into secondlow-voltage recess compartment 60. Next, electrically conductive polymer64 is cured, for example only, by the application of heat such thatelectrically conductive polymer 64 is no longer a liquid after beingcured. After electrically conductive polymer 64 has been cured,encapsulant 30 is dispensed, in liquid form, within case interior 52 tofill the remaining space within case interior 52. Next encapsulant 30 iscured, for example only, by the application of heat such thatencapsulant 30 is no longer a liquid after being cured.

Electrically connecting low-voltage end 46 of secondary winding 34 tolow-voltage terminal 50 directly through electrically conductive polymer64 eliminates the need for a costly and complex termination arrangementusing solder or other similar metal bonding operations. Similarly,electrically connecting high-voltage end 48 of secondary winding 34 tohigh-voltage terminal 44 directly through electrically conductivepolymer 64 eliminates the need for a costly and complex terminationarrangement using solder or other similar metal bonding operations.Electrically connecting high-voltage end 48 of secondary winding 34 tohigh-voltage terminal 44 directly through electrically conductivepolymer 64 also allows for simple and cost effective RFI suppressionsolutions. Furthermore, ignition coils with different placements ofhigh-voltage tower 42 may be needed to meet different packagingrequirements. Electrically connecting high-voltage end 48 of secondarywinding 34 to high-voltage terminal 44 directly through electricallyconductive polymer 64 allows for ignition coils with differentplacements of high-voltage tower 42 without the need to modify thesubassembly comprising core 16, high permeance structure 18, primarywinding spool 26, primary winding 28, and secondary winding spool 32.Instead case 36, can be tailored to shorten or lengthen high-voltagerecess channel 76 to accommodate the desired location of high-voltagetower 42. Modifying case 36 may be simpler and less costly than makingthe necessary modifications to the subassembly comprising core 16, highpermeance structure 18, primary winding spool 26, primary winding 28,and secondary winding spool 32 in order to achieve the desired locationof high-voltage tower 42.

While a specific configuration of ignition coil 10 has been described,it should be understood that the present invention is applicable for usein a variety of ignition coil configurations.

While electrically conductive polymer 64 has been described for use withboth low-voltage end 46 and high-voltage end 48 of secondary winding 34,it should now be understood that one end of secondary winding 34 may beconnected to its respective terminal using conventional techniques whilethe other end may be connected to its respective terminal withelectrically conductive polymer 64.

While electrically conductive polymer 64 has been described for use withboth low-voltage end 46 and high-voltage end 48 of secondary winding 34,it should now be understood that electrically conductive polymers ofdiffering compositions may be used for each end of secondary winding 34.

While this invention has been described in terms of preferredembodiments thereof, it is not intended to be so limited, but ratheronly to the extent set forth in the claims that follow.

We claim:
 1. An ignition coil for delivering a spark-generating currentto a spark plug; said ignition coil comprising: a magnetically-permeablecore; a primary winding disposed outward of said core; and a secondarywinding disposed outward of said primary winding and inductively coupledto said primary winding, said secondary winding terminating at one endthereof in a low-voltage end and terminating at another end thereof in ahigh-voltage end; wherein at least one of said low-voltage end of saidsecondary winding and said high-voltage end of said secondary winding iselectrically connected directly to a terminal through an electricallyconductive polymer; wherein said terminal is a high-voltage terminal andsaid high-voltage end of said secondary winding is electricallyconnected directly to said high-voltage terminal through saidelectrically conductive polymer; wherein said ignition coil furthercomprises a case defining an interior having an interior surface suchthat said core, said primary winding, and said secondary winding arereceived within said interior of said case, said interior surfacedefining a high-voltage recess therein such that said high-voltage endof said secondary winding, said high-voltage terminal, and saidelectrically conductive polymer are disposed within said high-voltagerecess; and wherein said ignition coil further comprises a secondarywinding spool upon which said secondary winding is wound, said secondarywinding spool having a high-voltage post extending therefrom such thatsaid high-voltage end of said secondary winding is wrapped around saidhigh-voltage post.
 2. An ignition coil as in claim 1 wherein saidhigh-voltage post is disposed within said high-voltage recess of saidcase.
 3. An ignition coil as in claim 1 wherein said high-voltage postis steel, whereby said high-voltage end of said secondary windingwrapped around said high-voltage post forms an inductor which reducesRFI in use.
 4. An ignition coil as in claim 2 wherein said high-voltagepost includes a retention feature for preventing said high-voltage endof said secondary winding from sliding on said high-voltage post whensaid high-voltage post and said high-voltage end of said secondarywinding are inserted into said high-voltage recess containing saidelectrically conductive polymer.
 5. An ignition coil as in claim 4wherein said retention feature is a step.
 6. An ignition coil fordelivering a spark-generating current to a spark plug; said ignitioncoil comprising: a magnetically-permeable core; a primary windingdisposed outward of said core; and a secondary winding disposed outwardof said primary winding and inductively coupled to said primary winding,said secondary winding terminating at one end thereof in a low-voltageend and terminating at another end thereof in a high-voltage end;wherein at least one of said low-voltage end of said secondary windingand said high-voltage end of said secondary winding is electricallyconnected directly to a terminal through an electrically conductivepolymer; wherein said terminal is a high-voltage terminal and saidhigh-voltage end of said secondary winding is electrically connecteddirectly to said high-voltage terminal through said electricallyconductive polymer; and wherein said ignition coil further comprises acase defining an interior having an interior surface such that saidcore, said primary winding, and said secondary winding are receivedwithin said interior of said case, said interior surface defining ahigh-voltage recess therein such that said high-voltage end of saidsecondary winding, said high-voltage terminal, and said electricallyconductive polymer are disposed within said high-voltage recess, whereinsaid high-voltage recess comprises: a first high-voltage recesscompartment with said high-voltage end of said secondary winding andsaid electrically conductive polymer disposed therein; a secondhigh-voltage recess compartment with said high-voltage terminal and saidelectrically conductive polymer disposed therein; and a high-voltagerecess channel connecting said first high-voltage recess compartment tosaid second high-voltage recess compartment with said electricallyconductive polymer disposed therein.
 7. An ignition coil as in claim 6wherein said high-voltage recess channel has a width that is narrowerthan said first high-voltage recess compartment and said secondhigh-voltage recess compartment.
 8. An ignition coil as in claim 6wherein said electrically conductive polymer within said high-voltagerecess channel acts as a resistor for reducing RFI in use.
 9. Anignition coil as in claim 8 wherein said electrically conductive polymerwithin said high-voltage recess channel has a resistance between about500 ohms and about 2000 ohms.
 10. An ignition coil as in claim 3 furthercomprising an inductor within said high-voltage recess between saidhigh-voltage end of said secondary winding and said high-voltageterminal which reduces RFI in use.
 11. A method of assembling anignition coil for delivering a spark-generating current to a spark plug,the ignition coil comprising a magnetically-permeable core, a primarywinding disposed outward of said core, a secondary winding disposedoutward of said primary winding and inductively coupled to said primarywinding, said secondary winding terminating at one end thereof in alow-voltage end and terminating at another end thereof in a high-voltageend, a case defining an interior having an interior surface defining ahigh-voltage recess therein, and a secondary winding spool upon whichsaid secondary winding is wound, said secondary winding spool having ahigh-voltage post extending therefrom; said method comprising: providingan electrically conductive polymer; using said electrically conductivepolymer to directly electrically connect at least one of saidlow-voltage end of said secondary winding and said high-voltage end ofsaid secondary winding to a terminal through said electricallyconductive polymer, wherein said terminal is a high-voltage terminal andsaid high-voltage end of said secondary winding is connected directlyelectrically to said high-voltage terminal through said electricallyconductive polymer; dispensing said electrically conductive polymerwithin said high-voltage recess; positioning said high-voltage end ofsaid secondary winding within said high-voltage recess, wherein saidstep of positioning said high-voltage end of said secondary windingwithin said high-voltage recess is after said step of dispensing saidelectrically conductive polymer and includes positioning saidhigh-voltage end of said secondary winding within said electricallyconductive polymer; and wrapping said high-voltage end of said secondarywinding around said high-voltage post before said step of positioningsaid high-voltage end of said secondary winding within said high-voltagerecess.
 12. A method as in claim 11 wherein said step of positioningsaid high-voltage end of said secondary winding within said electricallyconductive polymer includes positioning said high-voltage post withinsaid electrically conductive polymer.
 13. A method as in claim 11wherein said high-voltage post is steel, said method further comprisingusing said high-voltage end of said secondary winding and saidhigh-voltage post as an inductor to reduce RFI in use.
 14. A method ofassembling an ignition coil for delivering a spark-generating current toa spark plug, the ignition coil comprising a magnetically-permeablecore, a primary winding disposed outward of said core, a secondarywinding disposed outward of said primary winding and inductively coupledto said primary winding, said secondary winding terminating at one endthereof in a low-voltage end and terminating at another end thereof in ahigh-voltage end, and a case defining an interior having an interiorsurface defining a high-voltage recess therein, wherein saidhigh-voltage recess comprises a first high-voltage recess compartment, asecond high-voltage recess compartment, and a high-voltage recesschannel connecting said first high-voltage recess compartment to saidsecond high-voltage recess compartment; said method comprising:providing an electrically conductive polymer; using said electricallyconductive polymer to directly electrically connect at least one of saidlow-voltage end of said secondary winding and said high-voltage end ofsaid secondary winding to a terminal through said electricallyconductive polymer, wherein said terminal is a high-voltage terminal andsaid high-voltage end of said secondary winding is connected directlyelectrically to said high-voltage terminal through said electricallyconductive polymer; dispensing said electrically conductive polymerwithin said high-voltage recess; positioning said high-voltage end ofsaid secondary winding within said high-voltage recess; and positioningsaid high-voltage terminal within said high-voltage recess before saidstep of dispensing said electrically conductive polymer; wherein: saidstep of positioning said high-voltage end of said secondary windingwithin said high-voltage recess includes positioning said high-voltageend of said secondary winding within said first high-voltage recesscompartment; said step of positioning said high-voltage terminal withinsaid high-voltage recess includes positioning said high-voltage terminalwithin said second high-voltage recess compartment; and said step ofdispensing said electrically conductive polymer within said high-voltagerecess includes dispensing said electrically conductive polymer withinsaid first high-voltage recess compartment, said second high-voltagerecess compartment, and said high-voltage recess channel.
 15. A methodas in claim 14 wherein said high-voltage recess channel has a width thatis narrower than said first high-voltage recess compartment and saidsecond high-voltage recess compartment.
 16. A method as in claim 14further comprising using said electrically conductive polymer withinsaid high-voltage recess channel as a resistor to reduce RFI in use. 17.A method as in claim 16 wherein said electrically conductive polymerwithin said high-voltage recess channel has a resistance between about500 ohms and about 2000 ohms.
 18. An ignition coil for delivering aspark-generating current to a spark plug; said ignition coil comprising:a magnetically-permeable core; a primary winding disposed outward ofsaid core; a secondary winding disposed outward of said primary windingand inductively coupled to said primary winding, said secondary windingterminating at one end thereof in a low-voltage end and terminating atanother end thereof in a high-voltage end, wherein one of saidlow-voltage end of said secondary winding and said high-voltage end ofsaid secondary winding is electrically connected directly to a terminalthrough an electrically conductive polymer; a case defining an interiorhaving an interior surface such that said core, said primary winding,and said secondary winding are received within said interior of saidcase, said interior surface defining a recess therein such that said oneof said low-voltage end and said high-voltage end of said secondarywinding, said terminal, and said electrically conductive polymer aredisposed within said recess; and a secondary winding spool upon whichsaid secondary winding is wound, said secondary winding spool having apost extending therefrom such that said one of said low-voltage end andsaid high-voltage end of said secondary winding is wrapped around saidpost.
 19. An ignition coil as in claim 18 wherein said post is disposedwithin said recess of said case.
 20. An ignition coil as in claim 18wherein said post includes a retention feature for preventing said oneof said low-voltage end and said high-voltage end of said secondarywinding from sliding on said post when said post and said one of saidlow-voltage end and said high-voltage end of said secondary winding areinserted into said recess containing said electrically conductivepolymer.
 21. An ignition coil as in claim 20 wherein said retentionfeature is a step.
 22. An ignition coil as in claim 18 wherein saidrecess comprises: a first recess compartment with said one of saidlow-voltage end and said high-voltage end of said secondary winding andsaid electrically conductive polymer disposed therein; a second recesscompartment with said terminal and said electrically conductive polymerdisposed therein; and a recess channel connecting said first recesscompartment to said second recess compartment with said electricallyconductive polymer disposed therein.
 23. An ignition coil as in claim 22wherein said recess channel has a width that is narrower than said firstrecess compartment and said second recess compartment.